Lock promotion percent

page lock promotion PCT and row lock promotion PCT set the percentage of locked pages or rows (based on the table size) above which Adaptive Server attempts to acquire a table lock when the number of locks is between the lock promotion HWM and the lock promotion LWM.

The default value is 100.

Adaptive Server attempts to promote page locks to a table lock or row locks to a table lock when the number of locks on the table exceeds:

(PCT * number of pages or rows in the table) / 100

Setting lock promotion PCT to a very low value increases the chance of a particular user transaction acquiring a table lock. Figure 13-1 shows how Adaptive Server determines whether to promote page locks on a table to a table lock.

Figure 13-1: Lock promotion logic